To measure Vas, use a good solid enclosure of known volume that is approximately a cube of the nominal speaker size….1.1 Measuring Re, Fs, Qes, Qms and Qts.

Table of Contents

## How do you calculate VAS on a speaker?

To measure Vas, use a good solid enclosure of known volume that is approximately a cube of the nominal speaker size….1.1 Measuring Re, Fs, Qes, Qms and Qts.

Mechanical Q | Qms = Fs × √r0 / (Fh – Fl) |
---|---|

Total Q | Qts = Qms × Qes / (Qms + Qes) |

**How do you calculate displacement of a driver?**

Displacement, (Vd), is Area of Cone times Excursion. Excursion, if not listed, is: (length of voice coil – magnetic gap) divided by 2. Magnetic gap is also called air gap.

**How do you calculate driver volume?**

Put a plastic bag around the driver and put the driver upsidedown in the box. Pour in rice until the box is full. Measure the volume of the rice. Subtract this from the box volume to get the driver volume.

### What is the VAS of a speaker?

Vas: Vas is the volume of air that has the same compliance as the speaker’s suspension. Stiff speakers have lower Vas and tend to use small enclosures. Speakers with loose suspension have a higher Vas and use larger enclosures.

**What is the VAS of a subwoofer?**

air

Vas is an equivalent volume of air that has a compliance equal to that of the driver’s moving system.

**What does FS mean in speakers?**

Fs Driver free air resonance, in Hz. This is the point at which driver impedance is maximum. “This parameter is the free-air resonant frequency of a speaker. Simply stated, it is the point at which the weight of the moving parts of the speaker becomes balanced with the force of the speaker suspension when in motion.

## How do you calculate round port area?

The port area is in square inches, meaning it takes height times width to calculate total area. A port 4 inches high by 4 inches wide would calculate as 4 x 4= 16 in2.

**What is F3 speaker parameter?**

F3 is the frequency where the output is 3 db lower. If your Lp crossover is set at 80hz then it is 3db lower at 80hz. If the box has an f3 of 30hz that is the point it starts dropping off.

**What is VAS woofer?**

Vas is the equivalent compliance (inverse of stiffness) volume seen by a given diameter speaker cone, meaning the volume of box air that gives the same stiffness as the driver’s suspension.

### Is vas a driver displacement?

Vas is an equivalent volume of air that has a compliance equal to that of the driver’s moving system.

**What is XMax on a subwoofer?**

XMax = The distance a subwoofer voice coil can move in one direction without leaving the magnetic zone a.k.a. how far the woofer can move.